Lactoferrin (Lf) bacteriostatic activity was initially described in 1964. More recently, a bactericidal effect was reported, and Lf binding to the bacterial surface was demonstrated. In addition, Lf has been shown to bind DNA and anionic proteins, such as casein, immunoglobulins, and albumin. The overall objective of this investigation is to determine whether Lf is capable of binding certain viral proteins and thus inhibit viral infectivity. Initial studies will be performed with herpes simplex virus (HSV) for a number of reasons. First of all, my laboratory is not equipped for viral research. There are, however, commercially available cell line systems specifically designed for HSV cultured by "non- virologists". Additionally, antisera for the detection of HSV are readily available from several commercial sources. Lastly, HSV is a subject of much scientific interest as well as general public concern. The following factors will be investigated in this pilot study: 1. Determination of the effect of Lf on HSV infectivity to human foreskin fibroblast and/or Vero cells. 2. Demonstration of Lf binding to HSV and correlation of Lf binding with inhibition of HSV infectivity. 3. Investigation of a possible protective effect of Lf on the cells lines. These studies will determine if an observed reduction of viral infectivity was due to Lf interaction with the cells or with HSV. 4. Expansion of the investigation to include other viruses, such as cytomegalovirus, adenovirus, members of the enterovirus group, and/or respiratory syncytial virus.